1. Field
Aspects of embodiments of the present invention relate to a battery module.
2. Description of the Related Art
A rechargeable battery differs from a primary battery in that it can be repeatedly charged and discharged, while the latter makes only the irreversible conversion of chemical to electrical energy. A low-capacity rechargeable battery may be used as the power supply for small electronic devices, such as cellular phones, notebook computers, and camcorders, while a high-capacity rechargeable battery may be used as the power supply for driving motors in hybrid vehicles, electric vehicles, and the like.
A high-power rechargeable battery using a non-aqueous electrolyte with a high energy density has been recently developed. For example, the high-power rechargeable battery is constructed with a high-capacity rechargeable battery having a plurality of rechargeable cells coupled to each other in series such that it can be used as the power supply for driving motors in hybrid vehicles and electric vehicles requiring high power.
In addition, a large-capacity rechargeable battery generally includes a plurality of rechargeable batteries that are coupled in series, and the rechargeable battery may have cylindrical or prismatic shapes.
The prismatic-shaped rechargeable battery includes an electrode assembly that has an anode and a cathode with a separator interposed therebetween, a case having a space receiving the electrode assembly, and a cap plate that seals the case and has a terminal hole in which an electrode terminal is inserted, and the electrode terminal is electrically connected with the electrode assembly, inserted in the terminal hole, and protruded outside the case.
The electrode terminal is fixed to the cap plate by a nut, but there is a problem in that the nut may be loosened by continuous external vibration or shock. The loosened nut causes contact resistance inside the rechargeable batteries, such that the output and cycle-life of the rechargeable batteries are reduced.
A method for connecting a connecting member to the first terminal and the second terminal through resistance welding has been proposed to overcome the problem.
However, when the connecting member is made of a different material from that of the first terminal or the second terminal, there is a problem in that it is difficult to bond the connecting member and the terminals using resistance welding or ultrasonic welding because of different melting points.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.